A method and apparatus for providing welding power includes two power sources, each having an output. Control signals from a data control circuit selectively operate the main bipolar transistor and the main MOS transistor for determining the logic high and low states of the data output terminal during data output. The invention further provides novel models of insulin-resistant glucose transport disease states. The method can store address conversions in the NAND based memory, where the address conversions can relate logical addresses to a physical address. A keyboard and mobile communication device incorporate the switch configuration. A transmitting and receiving device is provided on the main circuit board of a franking machine for the purpose of communicating with the device in which optical signals are transmitted.